Over the last fifty years, David Yurman has gone from hawking sculptures in his Long Island high school cafeteria to turning a signature cable bracelet into a branded empire of objects women covet. Any Yurman ring is a great gift, but the Black Diamond Crossover Ring is a particularly good choice, blending Yurman's iconic twists with more than enough bling to grab her attention. Even better, it won't leave you broke. (davidyurman.com, $950)